You might also be interested in this AMA we held on r/databasedevelopment with two NVMe developers from Samsung.<p><a href="https://www.reddit.com/r/databasedevelopment/comments/1afpezz/samsung_nvme_developers_ama/" rel="nofollow">https://www.reddit.com/r/databasedevelopment/comments/1afpez...</a>
Something useful to know that wasn't mentioned: SSDs will corrupt data if sitting for extended periods without being powered on and thus should never be used for cold storage.<p>"There are considerations which should be made if you are planning on shutting down an SSD based system for an extended period. The JEDEC spec for Enterprise SSD drives requires that the drives retain data for a minimum of 3 months at 40C. This means that after 3 months of a system being powered off in an environment that is at 40C or less, there is a potential of data loss and/or drive failures. This power off time limitation is due to the physical characteristics of Flash SSD media's gradual loss of electrical charge over an extended power down period. There is a potential for data loss and/or flash cell characteristic shift, leading to drive failure."<p>* <a href="https://www.ibm.com/support/pages/potential-ssd-data-loss-after-extended-shutdown" rel="nofollow">https://www.ibm.com/support/pages/potential-ssd-data-loss-af...</a>
I always thought 'flash' was a holdover from early reprogrammable ROM technology, non-volatile memory that you could erase by literally flashing a literal flashbulb over a little window on the chip. I would've sworn in a court of law that I recall this being called "flashable" memory, that erasing it was called "flashing" it, and reprogramming it in general was called "reflashing" in a sort of synecdoche. And I'd have assumed that this was the fundamental origin of what became _electronically_ erasable ROM (EEPROM), which led to all the various NVRAM technologies we have now, with "flashing" sticking as the term for reprogramming it, even after you could do it electronically.<p>It looks like the story these days is that someone at Toshiba thought up the name out of the blue. I'm skeptical!
Two wonderful papers that are relevant:
1) <a href="https://pages.cs.wisc.edu/~jhe/eurosys17-he.pdf" rel="nofollow">https://pages.cs.wisc.edu/~jhe/eurosys17-he.pdf</a> 2) <a href="https://www.usenix.org/system/files/hotstorage19-paper-wu-kan.pdf" rel="nofollow">https://www.usenix.org/system/files/hotstorage19-paper-wu-ka...</a>
11 years ago, I did a 3 hour 'Introduction to Solid State Storage' at LOPSA-East 2013 that also covered how spinning disks worked, if anyone is interested.<p><a href="https://www.youtube.com/watch?v=G3wf1HMr6b0" rel="nofollow">https://www.youtube.com/watch?v=G3wf1HMr6b0</a><p>The SSD content starts at around 1 hour in:
<a href="https://youtu.be/G3wf1HMr6b0?si=5kdNeLGafrrU6Gmy&t=3573" rel="nofollow">https://youtu.be/G3wf1HMr6b0?si=5kdNeLGafrrU6Gmy&t=3573</a>
Discussed at the time:<p><i>Everything I Know About SSDs</i> - <a href="https://news.ycombinator.com/item?id=22054600">https://news.ycombinator.com/item?id=22054600</a> - Jan 2020 (185 comments)
little hard to understand why it's worth explaining the details if you're going to gloss over the issue of endurance and erase cycle limits.<p>if you do very little writing, you have nothing to worry about with SSD endurance. just read-disturb.<p>do you do very little writing?
There is a very good 5-part explanation from Branch Education:<p><a href="https://www.youtube.com/playlist?list=PL6rx9p3tbsMuk0jnC-dBdwb32Z1g7mD0j" rel="nofollow">https://www.youtube.com/playlist?list=PL6rx9p3tbsMuk0jnC-dBd...</a>